Petrochemical products such as oil and gas are ubiquitous in society and can be found in everything from gasoline to children's toys. Because of this, the demand for oil and gas remains high. In order to meet this high demand, it is important to locate oil and gas reserves in the Earth. Scientists and engineers conduct “surveys” utilizing, among other things, seismic and other wave exploration techniques to find oil and gas reservoirs within the Earth. These seismic exploration techniques often include controlling the emission of seismic energy into the Earth with a seismic source of energy (e.g., dynamite, air guns, vibrators, etc.), and monitoring the Earth's response to the seismic source with one or more receivers (which may each include one or more transducers used as sensors, for example, an accelerometer, a hydrophone, etc.). By observing the reflected seismic signals detected by the receiver during the survey, the geophysical data pertaining to reflected signals may be acquired and these signals may be used to form an image indicating the composition of the Earth near the survey location.
Conventional receivers may include one or more transducers used as accelerometers to measure vibrations, particle motion, acceleration, and so forth. For example, a 3-dimensional receiver may include three orthogonally oriented transducers. Each transducer may include a flexible cantilever beam and one or more piezoelectric elements bonded to the beam, as well as a proof mass attached to one end of the beam. When forces are exerted on the proof mass, the proof mass and the attached cantilever beam are deflected, causing stress of the piezoelectric elements. This stress of the piezoelectric elements results in a measurable change in the electric charge or voltage generated by the piezoelectric material forming the elements, which can be measured to determine the direction and magnitude of the deflection of the proof mass. The typical voltage output may be from several mV to hundreds of mV.
Conventional transducer designs often utilize piezoelectric material that is best suited for sensing normal stress imparted onto the piezoelectric material. Such material is well-suited to detecting some signals, but may be less efficient at detecting other signals, such as low-level signals which may be desirable to detect during seismic imaging. Accordingly, transducers that allow for detection of low-level signals (e.g., low frequency signals) that overcome one or more of the limitations of conventional approaches are desired.